Association of patellofemoral pain syndrome (PFPS) with quadratus lumborum and lower limb muscle tightness a cross-sectional study

Patellofemoral pain syndrome (PFPS) is characterized by peripatellar or retro patellar pain, as a result of changes in the physical and biochemical components of the patellofemoral joint. The main contributory factor is being the excessive load on the patellofemoral joint. The change in the flexibility of lower limb muscles is one of the factors for developing PFPS.To find the association of quadratus lumborum (QL) and lower limb muscles tightness in patients with unilateral PFPS.50 PFPS participants (21 male and 29 female) were included and assessed for muscle tightness on both affected and unaffected side. The QL, rectus femoris, hamstring, iliotibial band (ITB) and gastrocnemius tightness were measured using inch tape and mobile inclinometer. A Chi Square test and phi crammer's v criteria were used to check the association and the strength of it.A significant association was found between tightness of rectus femoris (PFPS-right Chi 19.99 p < 0.001; Phi-0.632, PFPS-left Chi-5.52 p = 0.019 and Phi- 0.332), gastrocnemius (PFPS-right Chi 8.78 p = 0.003; Phi-0.419, PFPS-left Chi- 11.41 p = 0.001; Phi- 0.478), iliotibial band (PFPS-right Chi 7.83 p = 0.005; Phi-0.396, PFPS left Chi-3.68 p = 0.055; Phi- 0.27). There was no significant association of hamstring tightness (PFPS-right Chi - 3.68 p = 0.055; Phi-0.055, PFPS left Chi-1.11 p = 0.291; Phi- 0.019) and QL (PFPS right Chi - 1.10 p = 0.293; Phi-0.293, PFPS left Chi-0.79 p = 0.372; Phi- 0.372).PFPS was associated with tightness of rectus femoris, gastrocnemius, ITB and no association found between hamstring and QL muscle tightness and PFPS.